/Engine/Source/Runtime/Slate/Public/Widgets/Views/SListView.h
Establishes a wholly new list of items being observed by the list. Wipes all existing state and requests and will fully rebuild on the next tick.
void SetItemsSource ( [TUniquePtr](API\Runtime\Core\Templates\TUniquePtr)< [UE::Slate::ItemsSource::IItemsSource](API\Runtime\Slate\Widgets\Views\IItemsSource)< ItemType >> Provider )